1. Field of the Invention
The invention relates to a heat dissipating assembly, more particularly to a heat dissipating assembly that can provide an even biasing force when applied to establish heat-conductive contact with an electronic component.
2. Description of the Related Art
FIGS. 1 and 2 illustrate a conventional heat dissipating device 8 provided on a circuit board 6 in a notebook computer (not shown) for dissipating heat generated by a central processing unit (CPU) 7 that is mounted on a first surface 61 of the circuit board 6 and that has an exposed die portion 71. The circuit board 6 further has a second surface 62 opposite to the first surface 61, and is formed with four through holes 63 extending from the first surface 61 to the second surface 62 and arranged around the CPU 7.
The conventional heat dissipating device 8 includes a heat transfer plate 81, a heat-conducting pipe 80 connected to the heat transfer plate 81, a heat sink 84 connected to the heat-conducting pipe 80 and mounted on the circuit board 6, and a base plate 82. The base plate 82 is disposed on the second surface 62 of the circuit board 6, and has four screw seats 822 extending upwardly therefrom. Each screw seat 822 extends through a corresponding one of the through holes 63 in the circuit board 6, and is formed with a screw hole 823. The heat transfer plate 81 is formed with four through holes 812 corresponding to the through holes 63 in the circuit board 6. Four spring-loaded screw fasteners 83 extend through the through holes 81 in the heat transfer plate 8 and the through holes 63 in the circuit board and engage in the screw holes 823 in the screw seats 822, respectively, such that the heat transfer plate 81 is secured on top of the CPU 7 to establish heat-conductive contact with the CPU 7.
During assembly, the screw fasteners 83 are threaded to the screw seats 822 one at a time. Therefore, as shown in FIG. 2, different pressures act on the different corners of the die portion 71 during threading of the screw fasteners 83. The different pressures, which may be higher than a suggested pressure of 100 psi, applied by the screw fasteners 83 may result in damage to the die portion 71 that would necessitate replacement of the damaged CPU.